Effects of 3,4-dimethylpyrazole phosphate (DMPP) on nitrification and the abundance and community composition of soil ammonia oxidizers in three land uses

Abstract

The application of the nitrification inhibitor, 3,4-dimethylpyrazole-phosphate (DMPP), is considered as an effective strategy to mitigate agricultural nitrogen loss. However, the inhibitory effect of DMPP on nitrification is variable and the importance of the soil microbial community composition to the variability is poorly understood. In this study, nine soils were collected across three land uses to investigate the impact of DMPP on nitrification and associated dynamics of ammonia oxidizers in a 28-day microcosm incubation. The results showed that the efficacy of DMPP at inhibiting net nitrification rates varied highly from no effect to 63.6 % during the first week of incubation. The abundance of ammonia-oxidizing bacteria (AOB), rather than ammoniaoxidizing archaea (AOA), was significantly correlated with nitrate concentrations across three land uses and significantly inhibited by DMPP addition. DMPP had higher efficacy in neutral and alkaline wheat and vegetable soils, compared with pasture soils. Canonical correspondence analysis suggested that soil pH was the most influential factor explaining the community composition of AOB and AOA in the collected soils. However, neither ammonium nitrate nor DMPP addition had a significant effect on the community composition of AOB or AOA during the incubation indicated by non-metric multidimensional scaling ordination. Taken together, our findings indicated that DMPP slowed nitrification by inhibiting the growth of AOB, and DMPP application affected the abundance of AOB more than the ammonia oxidizer community composition.

Nitrifier‐induced denitrification is an important source of soil nitrous oxide and can be inhibited by a nitrification inhibitor 3,4‐dimethylpyrazole phosphate

“…Overall, the high potential of DMPP in inhibiting nitrification and N 2 O production in alkaline soils could be supported by the competitive dominance of AOB under alkaline conditions (Shen et al ., ). The incapability of DMPP in acid soils was supported by our previous microcosm studies and DNA‐SIP results that AOA were the dominant ammonia oxidisers in acid soils and could not be effectively inhibited by DMPP (Shi et al ., ). Furthermore, the high soil organic matter contents in acid soils (Table ) could also result in high adsorption rate and therefore low availability (and thus inactivation) of DMPP (Roco and Blu, ).…”

Determining the influence of environmental and edaphic factors on the fate of the nitrification inhibitors DCD and DMPP in soil

“…In addition, the specific composition of organic matter and clays, which affects soil CEC, have been shown to affect DCD and DMPP efficacy (Zhang et al, 2004;Wu et al, 2007;Barth et al, 2008;McGeough et al, 2016). The lower recovery rates associated with DMPP and the UK soil may suggest a greater interaction with the organic fraction (Shi et al, 2016). Otherwise, the contrasting physico-chemical properties (Table 1) as well as climatic conditions (e.g.…”

Effect of urease and nitrification inhibitors on ammonia volatilization and abundance of N‐cycling genes in an agricultural soil

“…The addition of NBPT either decreased the activity and abundance of the bacterial and archaeal amoA gene ( Shi et al., ) or did not affect it at all ( Giovannini et al., ). The application of DMPP reduced the abundance of the amoA gene of ammonia‐oxidizing bacteria ( Yang et al., ; Ruser and Schulz , ; Duan et al., ) and ammonia‐oxidizing archaea ( Kleineidam et al., ; Shi et al., , ). Further, urease and nitrification inhibitors can also affect denitrification, the process by which is sequentially reduced to nitrite ( ), NO, N 2 O, and, finally, N 2 by the nitrate‐, nitrite‐, nitric oxide‐, and nitrous oxide‐reductase enzymes encoded by the napA / narG, nirK / nirS, norB , and nosZ genes, respectively ( Bueno et al., , and references therein).…”